Warming blanket having multiple inlets

ABSTRACT

The present invention relates to a blanket for use with forced air convection systems, wherein the blanket includes multiple inlet ports. By providing a blanket with multiple inlets, the user has the choice of positioning the air supply or blower unit and the supply hose on either side of the patient. In addition, in a preferred embodiment, the inlet ports are resealable, thus allowing the user to switch inlets during use.

This is a continuation-in-part application of U.S. application Ser. No.07/924,269 filed Jul. 3, 1992.

BACKGROUND

Hypothermia is a condition of subnormal body temperature and presentsserious consequences to the patient suffering therefrom. It has beenshown that nearly seventy five percent of all patients who undergosurgical procedures develop hypothermia. This equates to approximatelyfourteen million patients a year in the United States alone. Thehypothermic condition is brought on by many factors includinganesthesia, the air conditioning of the operating room, and the infusionof cold blood, I-V solutions, or irrigating fluids.

Several methods and products have been developed to help preventhypothermia from occurring; such as the use of infrared lamps, cottonblankets, and warm water mattresses. However, none of these methods andproducts have proven completely successful. In fact, it has been shownthat these methods and products can not even prevent the patients fromlosing their endogenous heat. (See Journal of Post Anesthesia Nursing,Vol. 5, No. 4, August 1990, pp 254-263).

Another method of helping to prevent hypothermia that has proven veryeffective is the use of forced warm air convection. As early as 1937, arefrigeration blanket using cold air convection was suggested in U.S.Pat. No. 2,093,834 to Gaugler. This blanket included a plurality oflayers for channeling air flow from an inlet port. Noninflatableportions were provided around the periphery of the blanket to secure theblanket around the body. Gaugler does not mention hypothermia treatmentand does not suggest that the blanket could be used to supply warm air.

U.S. Pat. No. 2,512,559 to Williams also relates to a blanket forproviding cooled air to a person. The blanket in Williams comprised aplurality of thin sheets of material connected together at a pluralityof discrete locations and connected together in a continuous line aboutthe peripheral edge. An air inlet was provided to communicate with spacebetween the sheets to allow cool air to be supplied thereto. Again, nomention of hypothermia treatment or the supply of warm air is made.

In U.S. Pat. No. 4,572,188 to Augustine et al, a forced air convectionsystem which can supply either cool or warm air to a blanket isdescribed. The blanket in Augustine et al comprises a plurality ofinflatable hollow tubes having their interiors connected togetherthrough transverse openings. An entry port is provided in the uppersurface of the blanket for admitting the cool or warm air and small exitports are provided through the lower surface to allow the cool or warmair to flow out toward a body covered by the blanket.

Other patents relating to the supply of cool or warm air to a personthrough an inflatable blanket include U.S. Pat. Nos. 4,660,388 toGreene, Jr.; 4,777,802 to Feher; and 4,867,230 to Voss. Each of thesepatents describe blankets having various attributes and configurationsto supply cool or warm air to the person.

While some of the above systems suggest use in the operating room, theyall possess similar disadvantages. In particular, for the system towork, the blanket must be attached to an air supply or blower unitthrough a hose. The placement of the hose during surgery can be crucial,as full access to the patient can be compromised if the hose must belocated in a position which the surgeon wants to occupy. The placementof the hose can create difficulties in locating other equipment such asI-V stands, monitors, etc. necessary for the surgical procedure.

Therefore, there is a need in the art for improvements to forced warmair convection systems.

OBJECTS OF THE INVENTION

It is one object of the present invention to provide a blanket for aforced warm air convection system that allows placement of an air supplyhose to be selectively chosen depending on the needs of the surgicalprocedure to be performed.

It is another object of the present invention to provide a blanket for aforced warm air convection system that allows placement of an air supplyhose to be changed during a surgical procedure.

SUMMARY OF THE INVENTION

The above objects and others are accomplished according to the presentinvention by providing a blanket for a warm air convection system havingmultiple (at least two) inlets, each such inlet having means wherebysuch inlet may be selectively closed or opened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a blanket for a forced warm air convectionsystem according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a plan view of a blanket, generally designated by referencenumeral 10, for a forced warm air convection system, wherein the blanket10, is appropriate for use in the operating room. The blanket 10, shownin FIG. 1 is an upper body blanket, designed to cover the upper bodyportions of a patient who is undergoing a surgical procedure to lowerbody portions. The blanket, 10, has a generally rectangular shape andinclude a head recess portion 20. The blanket 10, comprises two sheetsof material which are sealed together along their peripheral edges andare connected together at connection spot welds 50, discretely locatedon the interior surface portions of the sheets. By connecting the sheetsof the blanket 10, in this manner, the blanket 10, may be inflated bysupplying air to the interior chamber formed between the sheets ofmaterial.

The blanket 10, further includes a first inlet port 30, and a secondinlet port 40. Inlet ports 30, 40 are in communication with the interiorof the blanket 10, and may be used to supply air to the interior of theblanket 10, so as to inflate blanket 10. The lower surface (not shown)of the blanket 10, is provided with a plurality of small exit ports toallow warm air to escape from the blanket 10, toward a patient.

In use, the blanket 10, is placed over the upper body of a patient sothat the patient's head remains exposed within the head recess portion20, and the inlet ports 30, 40, are oriented in a direction pointingtoward the top of the head of the patient. In this position, one inletport will be located on each side of the patient's head.

The inlet ports 30, 40, may initially be closed by any suitable meanssuch as sealing, folding, taping, snapping, etc. In the case where theinlet has been permanently sealed, means such as a perforated tear stripmay be provided to enable easy opening of the inlet port selected foruse. However, such sealing of the inlet ports requires the user toselect the inlet port to be used prior to operation of the blanket 10,and does not allow switching to the other inlet port during use. This isbecause once the permanent seal for such an inlet port has been brokenor opened, it is not possible to re-close the inlet port.

Therefore, in a preferred embodiment, the inlet ports 30, 40 will beinitially closed by means that allow reclosing. In particular, meanssuch as an adhesive strip, double-sided tape, snaps, zippers, foldingflaps, folding wire or plastic bars, or a ziplock type seal, etc. may beutilized. In a most preferred embodiment, the inlet ports 30, 40 areinitially sealed by hook and loop fastener strips to allow easy openingand re-closing.

The blanket according to the present invention has several advantages.In particular, by providing a blanket with dual inlets, the user has thechoice of positioning the air supply or blower unit and the supply hoseon either side of the patient. In addition, by providing resealableinlet ports, the user may switch inlets during use. This is particularlyadvantageous in allowing the surgeon full access to the patient.

The provision of spot welds 50, to connect the separate sheets of theblanket 10, also is advantageous. In particular, the spot welds 50,allow the free flow of warm air in all directions and therefore allowfor better heat distribution within the blanket. This can be critical inreducing the occurrence of hot or cold spots within the blanket duringuse.

The blanket may be formed of any suitable material capable of beingsealed together at selected positions and having sufficient strength toallow inflation and adequate air distribution within the inflatedportion. Such materials include plastics, non-woven wood pulpcompositions, laminated plastic and wood pulp materials, andcombinations thereof.

It should be noted that the present invention is primarily concernedwith a blanket which can be used to supply warm air to a patient in theoperating room during a surgical procedure, so as to help prevent theoccurrence of hypothermia. However, it will be evident to one skilled inthe art that the blankets according to the present invention could beused in areas other than the operating room, such as in the recoveryroom, or in the patient's regular hospital room. Further, it will beevident to one skilled in the art that a source of pressurized cooledair could be provided to the blanket according to the present inventionto control body temperature of the patient under conditions ofhyperthermia.

In addition, while the present invention has been particularly describedby reference to a blanket having two inlets, it will be evident to oneskilled in the art that any number of inlets could be provided to enableeven greater flexibility of use. The placement of additional inlets islimited only by the need to maintain good air distribution and flowwithin the blanket.

It is also noted that it would be possible to connect a supply source ofwarm air to each of the inlets when using the blanket according to thepresent invention. Alternatively a single supply source could beconnected to each inlet using a multiply branched supply hose. Forexample, if there are two inlets, the supply hose could have a y-shapedconfiguration. Each of these embodiments of using the present invention,may be advantageous in providing more even heat distribution to allparts of the blanket.

The foregoing has been a description of certain preferred embodiments ofthe present invention, but is not intended to limit the invention in anyway. Rather, many modifications, variations and changes in details maybe made within the scope of the present invention.

What is claimed is:
 1. A blanket for use with a forced air convectionsystem,wherein said blanket includes an inflation chamber with multipleinlet ports; wherein said multiple inlet ports may be reversibly sealedwith a reversible sealing means comprising folding wire or plastic barssuch that at least one of said multiple inlet ports remains closed whenthe blanket is supplied with forced air.
 2. A blanket according to claim1, wherein said blanket includes two inlet ports.